Automatic stovepipe-damper.



Patented Oct. 7, I902.

R. G. SMITH &. J. H. MATHIS.

AUTOMATIC STOVEPIPE DAMPER.

(Application filed July 12, 1901.)

(No Modem WITNESSES F Nrrnn STATES PATENT OFFICE.

ROBERT GIDEON SMITH AND JOHN HARRISON MATHIS, OF FORREST CITY, ARKANSAS.

AUTOMATlC STOVEPlPE-DAM PER.

SPECIFICATION forming part of Letters Patent No. 710,901, dated October '7, 1902.

Application filed July 12,1901. Serial No. 67,991. (No model.)

To (all whom it may concern:

Be it known that we, ROBERT GIDEON SMITH and JOHN HARRISON MATHIs, citizens of the United States, and residents of Forrest City,

in the county of St. Francis and State of Arkansas, have invented a new and Improved Automatic Stovepipe-Damper, of which the followingis a full, clear, and exact description.

The object of our invention is to provide the draft-pipe of a furnace, range, or heating or cooking stove with a novel simple appliance which is operated by the expansion and contraction of the draft-pipe, due to changes in its temperature, so as to correspondingly adjust a damper in the pipe, and thus automatically control draft therethrough, the damper being applicable to both vertical and horizontal pipes or ducts.

The invention consists in the novel construction and combination of parts, as is hereinafter described, and defined in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a side view of a joint of stovepipe or the like and of the improvement thereon. Fig. 2 is a longitudinal sectional View substantially on the 1ine2 2 in Fig. 1, and Fig. 3 is a transverse sectional view substantially on the line 3 3 in Fig. 1.

The joint or section 4 of a draft-pipe may be a portion of such a tubular conduit on a stove used for heating or cooking purposes or the draft-pipe for a heating-furnace, and, as shown, is formed of sheet-iron, having a suitable d aineterand length to suit the purpose for which it is designed.

The usual plate-like damper 5 is held to rock within the pipe-section 4: by the transverselydisposed crank rod 6, which is inserted through clip-bands 5, formed on the damper at or near its center of length, as shown clearly in Fig. 2, the position of said damper in the pipe-section being preferably near the longitudinal center of the latter. The rod 6 is journaled in opposite perforations in the wall of the pipe-section 4 and at one end is formed with a crank-arm 7. Near one end of the pipe-section 4 a bracket 8, in flattened loop form, is secured, and upon said bracket-sun port the pendent lever 9 is pivoted, as follows: Thelever 9 is bent atone end to produce the lateral arm 9, which hasloose engagement with the flattened surface of the bracket 8, and the pivot a serves to loosely secure the arm upon the bracket, the straight body of the lever extending parallel with the pipesection l.

A slot b is formed longitudinally in the lower portion of the lever 9, and the wrist-pin 0, formed on the outer end of the crank-arm 7, loosely engages within said slot.

Through a vertical perforation in the outer 05 end of the arm 9 the threaded upper end of the straight bar 10 is passed upwardly a sufficient distance to receive the coiled spring d, said portion of the bar having'anutescrewed on it before its insertion through the arm and a nut e on the extremity thereof which projects above the spring.

The bar 10 is of a length sufficient to dispose its lower end near the lower end of the pipe-section 4, and said endis secured on the bracket-piece 11, that may be the duplicate of the bracket 8, whereby the bar is held projected at the side of the pipe{- section far enough therefrom to permit the bar to remain measurably cool when the pipe-section is heated by use as a conductor of hot products of combustion from the stoveor the like to a chimney or other flue for transfer to the outer air.

The damper 5 is so disposed by its connection with the lever 9 as to be held nearly upright or in open adjustment when the stovepipe (of which the joint 4 is a portion) is not highly heated. In use the damper 5 remains in opened adjustment while the fire in the stove having the pipe as a smoke-conductor is in suitable condition for a proper heating of the stove. In case the heat increases beyond a proper degree the Stovepipe-section 4 will become lengthened by its corresponding 5 increase in temperature from the heat of the stove, and this will cause the bar 10 to pull on the arm 9 and rock. the lever 9, so as to rock the damper 5 toward a closed position and. when maximum heat is attained close said damper completely, as indicated by dotted lines in Fig. 1.

The bar 10 is connected fast at one end to the pipe, while its other end is slidably fitted to the lever, said end of the bar arranged to push in one direction against the lever and the movement of the bar in the opposite direction being opposed by the spring. This spring aifords'a yieldable resistance to the movement of the bar in one direction, so as to prevent breakage or rupture of the parts in case of excessive heating and expansion of the pipe, thus preserving the parts intact under all conditions. The spring also permits the lever to be moved a limited distance on the bar in case the damper becomes wedged or fastened in the pipe, thus allowing release of the damper without dismantling the regulator.

It is claimed that the improvement is ex tremely simple, is practical and reliable in operation, and is automatic in action as to the opening and closure of the damper in unison with the change in temperature of the draft-pipe whereon the damper-regulator is applied for service.

Having thus described our invention, we claim as new and desire to secure by Letters Patent-- 1. In an automatic damper-regulator, the combination with a stovepipe and a pivoted damper having a crank, of a bracket 8 fixed to said pipe, a lever 9 having a short portion or arm at substantially right angles to the main portion, and provided with a slot near one end of its long portion, said short portion or arm being fulcrumed on the bracket and said slot loosely receiving the crank of the damper, a rod arranged alongside of the lever and attached at one end directly to the stovepipe, and having a threaded end fitted slidably in an opening of the short portion of the lever, nuts screwed on the threaded part of said rod, and a spring fitted between the short arm of the lever and one of said nuts, the other not of the rod affording a fixed point of resistance to the lever, and adapted to shift the latter and the damper on the contraction of the pipe.

2. In an automatic damper-regulator, the combination with a stovepipe and a pivoted damper, of a lever connected with said damper and having a short portion or arm at substantially right angles to the main portion, said short portion or arm being fulcrumed on the pipe and provided with an opening, a rod disposed alongside of the pipe and fitted loosely or slidably in said opening of the short lever-arm, nuts rigidly mounted on the rod and disposed on opposite sides of said leverarm, one of said nuts normally engaging with the lever-arm and affording a fixed point of resistance to the lever, and a spring inter posed between the other nut and said short lever-arm.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

ROBERT GIDEON SMITH. JOHN HARRISON MATHIS.

Witnesses:

THEO. II. EYCK, J 1:, JOHN H. FISCHER. 

